Usually rcu_dereference isn't necessary in situations were the RCU-protected data structure cannot change, but sparse and lockdep still need a similar functionality for analysis. rcu_dereference_protected implements the reduced version which should be used to support the dynamic and static analysis.
Signed-off-by: Sven Eckelmann sven@narfation.org --- compat.h | 2 ++ gateway_client.c | 2 +- hard-interface.c | 2 +- soft-interface.c | 3 ++- 4 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/compat.h b/compat.h index fb49f9d..c11f6cd 100644 --- a/compat.h +++ b/compat.h @@ -265,6 +265,8 @@ int bat_seq_printf(struct seq_file *m, const char *f, ...); pos && ({ prefetch(pos->next); 1; }); \ pos = rcu_dereference(hlist_next_rcu(pos)))
+#define rcu_dereference_protected(p, c) (p) + #endif /* < KERNEL_VERSION(2, 6, 34) */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36) diff --git a/gateway_client.c b/gateway_client.c index 0df6e69..9fc475f 100644 --- a/gateway_client.c +++ b/gateway_client.c @@ -94,7 +94,7 @@ static void gw_select(struct bat_priv *bat_priv, struct gw_node *new_gw_node) if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount)) new_gw_node = NULL;
- curr_gw_node = bat_priv->curr_gw; + curr_gw_node = rcu_dereference_protected(bat_priv->curr_gw, 1); rcu_assign_pointer(bat_priv->curr_gw, new_gw_node);
if (curr_gw_node) diff --git a/hard-interface.c b/hard-interface.c index e0052cf..a3fbfb5 100644 --- a/hard-interface.c +++ b/hard-interface.c @@ -138,7 +138,7 @@ static void primary_if_select(struct bat_priv *bat_priv, if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount)) new_hard_iface = NULL;
- curr_hard_iface = bat_priv->primary_if; + curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1); rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
if (curr_hard_iface) diff --git a/soft-interface.c b/soft-interface.c index 515629e..56f1908 100644 --- a/soft-interface.c +++ b/soft-interface.c @@ -249,7 +249,8 @@ static void softif_neigh_vid_select(struct bat_priv *bat_priv, if (new_neigh && !atomic_inc_not_zero(&new_neigh->refcount)) new_neigh = NULL;
- curr_neigh = softif_neigh_vid->softif_neigh; + curr_neigh = rcu_dereference_protected(softif_neigh_vid->softif_neigh, + 1); rcu_assign_pointer(softif_neigh_vid->softif_neigh, new_neigh);
if ((curr_neigh) && (!new_neigh))